Powder filling method, powder filling device, and powder filling nozzle

ABSTRACT

A powder filling nozzle is used for filling up a container with a powder mixed with a gas and in a fluidized state. The power filling nozzle comprises a tubular body having an opening for discharging the powder in the fluidized state into the container, and a gas separating unit disposed near the opening of the tubular body and allowing the gas delivered together with the powder in the tubular body to pass through the gas separating unit but not allowing the powder to pass through the gas separating unit. The gas separating unit serves to set the opening in a plugged state by the powder separated from the gas, so that the delivery of the powder from the tubular body into the container is stopped.

TECHNICAL FIELD

The present invention generally relates to the technology for filling upa container with minute powder represented by the toner for imageformation by an electrophotographic printing system. In particular, thepresent invention relates to a powder filling method, a powder fillingdevice, and a powder filling nozzle for efficiently filling powder intoa small-inlet container or a small-capacity container the filling ofwhich is difficult or impossible by a conventional system.

BACKGROUND ART

There are various types of powder filling methods for filling up acontainer with the powder, such as a toner for electrophotographicprinting, which include a rotary valve type, a screw feeder type and anauger type. The fundamental concept of these methods is to drop thepowder by its gravity from the powder filling device to the containerdisposed under the powder filling device, so that the container isfilled up with the powder.

Especially, the auger-type powder filling method is well known and putin practical use. This method is considered as an efficient method forfilling up a container of a fixed capacity with the powder. See JapaneseLaid-Open Patent Applications No. 04-087901 and No. 06-263101.

Immediately after the container is filled up with the powder by thesepowder filling methods, a certain amount of air is contained in thepowder. In order that a large amount of powder is stored in ahigh-density state in the container for a short time, a powder fillingmethod has been proposed. In this method, the suction pipe is insertedin the container and one end of the suction pipe is embedded in thepowder in the container so that the air contained in the powder isreduced. See Japanese Laid-Open Patent Application No. 09-193902.

Usually, according to the auger-type powder filling method, thescrew-like auger is provided inside the conical hopper near the outletof the hopper, and the auger is rotated so that the toner within thehopper is discharged downward from the outlet. This procedure is carriedout by filling the toner into one of the plurality of containersarranged and conveyed on the transport belt one by one.

In recent years, with respect to the image formation using theelectrophotographic printing, there is the increasing demand forhigh-speed, high-clearness, high-quality image formation. With thistrend, consideration is taken to the toner from the several standpoints:the average particle size of the toner is made to 10 micrometers orless, the fluidity is increased by applying metal oxide particles (theexternal additive) to the surface of the toner, and the low-temperaturefixability of the toner is ensured by using a binding-agent resin of alow melting point.

However, the toner is pressurized by rotation of the auger in the caseof the above-mentioned method, and the external additive of the tonerwill be separated or isolated from the surface. Furthermore, in the caseof the auger type method, the external additive is buried in the toner,and the original function of increasing the fluidity by the externaladditive is eliminated or lost.

Moreover, in the case of the low-temperature fixing toner using abinding agent resin of a low melting point, the sticking of tonerparticles or aggregation is likely to occur since the toner ispressurized by rotation of the auger. Sometime the toner solidifies sothat the aggregation does not return to the original state. As a result,the outlet of the hopper is clogged with the toner particles and thedischarging is stopped. The problem that the toner filling work isinterfered arises.

When the copying is performed with the developer in which the toner andthe aggregation coexist, the quality of the reproduced image becomesinadequate since the aggregation has not a desired value of theelectrostatic property.

The smaller the toner particle diameter is, the more the toner fallsfrom the hopper to the container. The Brownian movement of such tonerparticles occurs in a gas regardless of the quality of the material. Andit becomes easy to make an atomizing state. Then, the necessity ofdischarging a large amount of gas existing in the powder particles willarise, and it is difficult to form the high-density filling state of thetoner in the container. It is desirable that the above-mentioned problemis solved to overcome such difficulty conjointly.

As described above, the auger type method requires a large-scale machineincluding the toner filling device having at least the hopper and thetransport belt carrying and conveying the plurality of containers. Andit is necessary that the container is arranged just below the tonerfilling device and filled up with the toner. Thus, the auger type methodhas the problem in that the arrangement of the toner filling device isfixed and several restrictions exist.

Another powder filling method has been proposed. In this method, gas isintroduced to the powder filling device which stores the powder similarto the hopper, and the fluidity of the powder is increased. While theagitator is rotated, the powder from the outlet of the powder fillingdevice is delivered to the container through the conveyance piping, andthe gas existing in the powder particles is discharged through thede-aeration piping before the powder reaches the container. Theobjective of the proposed method is to supply the powder efficiently andfilling up the container with the powder in a high-density state. SeeJapanese Laid-Open Patent Application No. 2001-031002.

However, the proposed method requires a large-scale powder fillingdevice in which the de-aeration piping is accurately disposed co-axiallywith the powder filling piping. The manufacture of such powder fillingdevice is difficult, and the weight becomes large.

Moreover, the powder filling device and the contained are disposed atseparate locations. When a small-diameter container or a container inwhich the internal wall of the container is configured in the shape of aspiral convex or others is used in order to facilitate the tonerdischarging, the delivery of the powder is prevented and mixing thepowder in the container with the air is difficult.

Moreover, since the de-aeration of the powder is performed in the courseof delivery of the powder to the container, the delivery of the powderis difficult. Moreover, since the agitator is used to discharge thepowder from the powder filling device, the separation of the externaladditive from the powder and the generation of aggregation will arisesimilar to the auger type method, and it is difficult to attain desiredfilling of the powder in the container.

Another powder filling method has been proposed. In this method, anauger-type powder filling device for filling a powder such as a medicalsupply or food into a container, such as a plastic bag. And the filterlayer is provided in the cylindrical wall surrounding the augerconnected with the lower part of the hopper, and the de-aeration of thegas existing in the powder is performed through the filter layer. By thede-aeration the negative pressure is generated, and the powder fallingto the plastic bag by rotation of the auger is stopped. See JapaneseLaid-Open Patent Application No. 2000-247445.

However, the proposed method uses the auger type method, and theabove-mentioned problems still remain unresolved. In the case of thetoner powder in which the external additive adheres, the separation ofthe external additive from the powder easily arises when the powderpasses through the inside of the rotating auger. When the externaladditive whose particle diameter is smaller than that of the powder isattracted through the filter layer, clogging of the filter layer mayoccur, and it is difficult to attain appropriate stopping function ofthe filter layer.

In an office where an image forming device, such as a copier or aprinter, is installed, when the developing unit of the device or thetoner container is directly replenished with the toner, the particulateof the toner is produced. Even if it is replenished, the toner containsa certain amount of air and it is set in a low density state.

When the toner is supplied to the developing unit having a complicatedstructure directly, the filling state does not become uniform and thevoid is created so that the quality of the reproduced image becomespoor.

The inventors have proposed a powder fluidization unit for solving theabove-mentioned problems in the toner filling method as disclosed inJapanese Patent Application No. 2001-102264.

The proposed powder fluidization unit is different from the auger typemethod mentioned above. In this powder fluidization unit, a minimumquantity of gas is introduced uniformly into the powder within thepowder fluidization unit, and a fluidized state of the powder isacquired. After that, the powder in the fluidized state is supplied bypressurization into the container separated from the powder fluidizationunit so that the container is filled up with the powder.

According to the above-mentioned powder filling method proposed by theinventors, it is possible to eliminate the separation of the externaladditive from the toner powder or the generation of the aggregationcaused by rotation of the auger as in the auger type method. Moreover,the powder filling device is made small, carrying it is easy, theoperation is easy, and it is very effective in eliminating theabove-mentioned problems. Therefore it is possible to perform thefilling of a small-inlet container or a complicated-shaped containerwith the powder sufficiently.

According to the above-mentioned powder filling method, the powder inthe fluidized state, produced within the powder fluidization unit, canflow into the container through the transport pipe at high speed sinceit is fluidized and pressurized. The container can be immediately filledwith the powder and the gas.

An important technical matter for filling each of the plurality ofcontainers with the powder of the given quantity continuously one by oneis to provide a controllable method so that the incoming flow is stoppedinstantly after one container is filled up with the powder of a givenquantity, and the incoming flow can resumed for the following containerso that the following container can also be filled up with the powder ofthe given quantity.

If that control cannot be performed enough, the powder is atomizedaround the powder filling device and the powder stain may occur.Although the inventors adjusted the pressure open valve provided in theabove-mentioned conventional powder fluidization unit and controlled thedelivery pressure, it is found that the feature of stopping the powderflow into the container instantly is inadequate.

It is conceivable that the cause of the above problem is that, because acertain time for escaping the air from the pressure open valve isneeded, the falling of the residual pressure takes some time and thedistance from the powder fluidization unit to the container is too long.

Moreover, the inventors provided the mechanical stop units, such as thevalve or the shutter, at the edge of the powder filling nozzle beinginserted into the container as the pressure control unit. As the fillingoperation is performed repeatedly, the aggregation of the powder isformed. It has been confirmed that the stop control of the powderfilling is not performed adequately. It is conceivable that the cause ofthe above problem is that the powder is pressurized by the mechanicalstop unit.

DISCLOSURE OF THE INVENTION

A general object of the present invention is to provide an improvedpowder filling method in which the above-mentioned problems areeliminated.

A more specific object of the present invention is to provide a powderfilling device and method which makes it possible to realize controlwhich stops the delivery of the powder to the container instantly,without deteriorating the powder, and to fill up the container with thepowder of the given quantity in a high-density state.

Especially the present invention aims at offering a powder fillingnozzle which can solve the above-mentioned problems in the case offilling the container with the toner used for the development of anelectrostatic latent image.

In order to achieve the above-mentioned objects, the present inventionprovides a powder filling nozzle used for filling up a container with apowder mixed with a gas and in a fluidized state, the powder fillingnozzle comprising: a tubular body having an opening for discharging thepowder in the fluidized state into the container; and a gas separatingunit disposed near the opening of the tubular body and allowing the gasdelivered together with the powder in the tubular body to pass throughthe gas separating unit but not allowing the powder to pass through thegas separating unit, wherein the gas separating unit serves to set theopening in a plugged state by the powder separated from the gas, so thatthe delivery of the powder from the tubular body into the container isstopped.

In order to achieve the above-mentioned objects, the present inventionprovides a powder filling device including a hermitically sealed powderfluidization unit and a powder filling nozzle, the powder filling devicefilling a powder, mixed with a gas and changed to a fluidized state bythe powder fluidization unit, into a container through a delivery pathby using the powder filling nozzle, the powder filling nozzlecomprising: a tubular body having an opening for discharging the powderin the fluidized state into the container; and a gas separating unitdisposed near the opening of the tubular body and allowing the gasdelivered together with the powder in the tubular body to pass throughthe gas separating unit but not allowing the powder to pass through thegas separating unit, wherein the gas separating unit serves to set theopening in a plugged state by the powder separated from the gas, so thatthe delivery of the powder from the tubular body into the container isstopped.

In order to achieve the above-mentioned objects, the present inventionprovides a powder filling method for filling up a container with apowder in a fluidized state by using a powder filling device whichincludes a hermitically sealed powder fluidization unit and a powderfilling nozzle, the powder filling nozzle comprising a tubular bodyhaving an opening for discharging the powder in the fluidized state intothe container, and a gas separating unit disposed near the opening ofthe tubular body and allowing a gas delivered together with the powderin the tubular body to pass through the gas separating unit but notallowing the powder to pass through the gas separating unit, the powderfilling method comprising the steps of: mixing the powder contained inthe powder fluidization unit with the gas to obtain the powder in thefluidized state; delivering the powder in the fluidized state from thefluid fluidization unit into the powder filling nozzle via a deliverypath so that the powder is discharged into the container from the powderfilling nozzle; and setting the opening of the tubular body in a pluggedstate by the powder separated from the gas by the gas separating unit sothat the delivery of the powder from the tubular body to the containeris stopped.

According to the present invention, the powder filling nozzle, powderfilling device, and powder filling method which make it possible to fillup the container with the powder of a given amount in a high-densitystate efficiently and precisely.

Other objects, features and advantages of the present invention will beapparent from the following detailed description when reading inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing the first embodiment of the powderfilling device of the present invention.

FIG. 2 is a schematic diagram showing the second embodiment of thepowder filling device of the present invention.

FIG. 3 is a cross-sectional view showing an example of the powderfilling nozzle of the double pipe structure of the present invention.

FIG. 4A is a cross-sectional view showing an example of the powderfilling nozzle of the triple pipe structure of the present invention,and FIG. 4B is a diagram showing the third tubular body with two or morethrough holes formed in the powder filling nozzle.

FIG. 5A is a cross-sectional view showing the modification of the powderfilling nozzle of the double pipe structure of the present invention,and FIG. 5B is a cross-sectional view of the first tubular body of thepowder filling nozzle of FIG. 5A taken along the line B-B.

FIG. 6 is a diagram for explaining the powder delivery stop function ofthe powder filling nozzle of the present invention.

FIG. 7 is a diagram for explaining the high-density powder fillingfunction of the powder filling nozzle of the triple pipe structure ofthe present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Before explaining a preferred embodiment of the invention, the powderfluidization unit for solving the above-mentioned problems in the tonerfilling method which is previously proposed by the inventors will beexplained in order to make the understanding of the invention easy.

The proposed powder fluidization unit differs from the method of storingthe powder into the container as in the auger type method in which thepowder from the powder filling device is agitated and made to fall tothe container. In this powder fluidization unit, a minimum quantity ofgas is introduced uniformly into the powder within the powderfluidization unit, and a fluidized state of the powder is acquired.After that, the powder in the fluidized state is supplied bypressurization into the container separated from the powder fluidizationunit so that the container is filled up with the powder.

The above-mentioned powder fluidization unit will be explained, togetherwith the powder filling device which is an embodiment of the invention,with reference to FIG. 1 and FIG. 2. In FIG. 2, the elements which arethe same as the corresponding elements in FIG. 1 are designated by thesame reference numerals and have the same meaning.

The main functional devices of the powder filling device shown in FIG. 1and FIG. 2 are the powder fluidization unit 10 and the powder fillingnozzle 17. The powder fluidization unit 10 is hermitically sealed. Atthe bottom of the powder fluidization unit 10, the air introductory partis provided for fluidizing the powder.

The powder delivery tube 24 is inserted beforehand to the powderfluidization unit 10, one end of the powder delivery tube is connectedto the flow powder transport pipe 12, and the other end of the flowpowder transport pipe 12 is connected to the powder filling nozzle 17 ofthe invention.

Furthermore, the other end of the flow powder transport pipe 12 isconnected to one end of the powder filling nozzle 17. The other end ofthe powder filling nozzle 17 which is not connected with the flow powdertransport pipe 12 is placed into the container 18 for filling the powderso that the nozzle end does not contact the bottom of the powdercontainer 18.

When the powder filling device operates, the powder to be filled intothe container is first injected to the powder fluidization unit 10 fromthe powder entrance slot 11 with the closing valve, and the pressureopen valve 13 for opening and sealing the internal pressure is opened.

On the other hand, the operation of the powder flow velocity controlvalve 15 for fine adjustment of the pressure may be automated with anelectromagnetic valve or carried out by the human power.

After the powder is injected, the pressure open valve 13 is closed, andthe gas is introduced from the vent pipe 7 into the air header 3 whichis a pressurization accumulator as the gas introducing unit.

The incoming flow of the gas may be adjusted by the first reducing valve25 and the second reducing valve 26 which serve as the pressureregulation and flow rate adjustment unit. During operation of the powderfilling device, the incoming flow is continued.

The introduced gas passes through the ventilation porous plate 2 so thatit is distributed uniformly in the powder and the powder is changed intoa fluidized state.

While the pressure open valve 13 is closed, the powder 28 in thefluidized state is extruded from the inside of the powder fluidizationunit 10 to the powder transport pipe 12 by the pressure of the gas usedfor the fluidization. The powder in the fluidized state from the end ofthe tubular filling nozzle 17 is discharged into the container 18. Theend of the tubular filling nozzle 17 is placed inside the container 18.

The flow powder transport pipe 12 may be made of a flexible material,and the length of the flow powder transport pipe 12 is not limited to aspecific length if only it shows the above-mentioned function. It ispossible to arrange the powder fluidization unit 10 and the container 18so that they are separated from each other.

In the above-described powder filling device, at the initial stage offilling, especially when the inside of the container 18 is completelyempty, the degree of opening of the powder flow velocity control valve15 of the powder fluidization unit 10 is adjusted so that the speed ofdischarging of the fluidized-state powder from the powder fluidizationunit 10 into the container 18 is set to a moderate speed. This is donein order to avoid irregularity or excessive diffusion.

Subsequently, after the quantity of the powder cloud existing in thecontainer 18 increases to such a level that the flow of thefluidized-state powder discharged from the end of the powder fillingnozzle 17 can be almost surrounded by the powder cloud, the powder flowvelocity control valve 15 is set to a widely open state, and the fillingoperation is continued.

According to the powder filling method proposed by the inventors, it ispossible to eliminate the separation of the external additive from thepowder or the generation of the aggregation caused by rotation of theauger as in the auger type method. Moreover, the powder filling deviceis made small, carrying it is easy, the operation is easy, and it isvery effective in eliminating the above-mentioned problems. Therefore itis possible to perform the filling of a small-inlet container or acomplicated-shaped container with the powder sufficiently.

According to the powder filling method, the powder in the fluidizedstate created within the powder fluidization unit is pressurized, andcan flow into the container through the transport pipe at high speed.The container can be immediately filled with the powder and the gas. Forthis reason, in order to fill each of two or more containers with thepowder of the given quantity continuously one by one, it is necessary toprovide a controllable method so that the incoming flow of the powder isstopped instantly if one container is filled up with the powder of thegiven quantity, and the incoming flow of the powder or the delivery isresumed for filling the following container with the powder.

If that control cannot be performed enough, the powder is atomizedaround the powder filling device and the powder stain may occur.

Although the pressure open valve 13 provided in the powder fluidizationunit 10 is adjusted and the delivery pressure is controlled, it is foundthat the feature of stopping the powder flow into the containerinstantly according to the powder filling method is inadequate.

It is conceivable that the cause of the above problem is that, because acertain time for escaping the air from the pressure open valve isneeded, the falling of the residual pressure takes some time and thedistance from the powder fluidization unit to the container is too long.

Moreover, the mechanical stop units, such as the valve or the shutter,are provided at the edge of the powder filling nozzle being insertedinto the container as the pressure control unit according to the powderfilling method. However, as the filling operation is performedrepeatedly, the aggregation of the powder is formed. It has beenconfirmed that the stop control of the powder filling is not performedenough. It is conceivable that the cause of the above problem is thatthe powder is pressurized by the mechanical stop unit.

In order to solve the above-mentioned problems, the first aspect of thepresent invention is to provide a powder filling nozzle which realizesthe control to stop the delivery of the powder to the containerinstantly without deteriorating the powder in the powder filling methodwhich acquires the powder in a fluidized state by introducing the gasinto the powder flow in the container, and fills up the container withthe powder in the fluidized state.

Next, the outline composition of the powder filling nozzle of theinvention will be explained.

The powder filling nozzle of the invention is used to fill up thecontainer with the powder mixed with the gas and in the fluidized state,and comprises a tubular body having an opening for discharging thepowder in the fluidized state into the container, and a gas separatingunit disposed near the opening of the tubular body and allowing the gasdelivered together with the powder in the tubular body to pass throughthe gas separating unit but not allowing the powder to pass through thegas separating unit. The gas separating unit serves to set the openingin a plugged state by the powder separated from the gas so that thedelivery of the powder from the tubular body into the container isstopped.

Usually, the powder in the fluidized state delivers well, and it isnecessary that in the filling work the discharge of the powder from thepowder filling nozzle be stopped instantly if the powder of the givenquantity is supplied to the container.

The mechanical pressure is not applied according to the above-describedpowder filling nozzle of the present embodiment, and the delivery of thepowder in the fluidized can be stopped instantly, without separation ofthe external additive and generation of the aggregation, which may causethe quality of an image formed by the toner for electrophotographicprinting to deteriorate. It is possible to efficiently carry out thefilling work and accurately control the quantity of the powder beingfilled into the container.

Next, two examples of the powder filling nozzle of the invention will beexplained.

One example is a powder filling nozzle of double pipe structureincluding a small-diameter tubular body (called first tubular body) anda large-diameter tubular body (called second tubular body). The firsttubular body is inserted into the second tubular body, so that a gapbetween the two tubular bodies is formed as a gas delivery path. Bothends of the two tubular bodies are fixed so as to close the gap.

And the first tubular body serves as a delivery path which dischargesthe powder in the fluidized state fed from one opening of the firsttubular body into the container through the other opening thereof.

The circumference of the neighborhood of the discharge side opening isformed by a filter material which does not pass the powder therethroughbut allow the gas to pass therethrough. The second tubular body has agas exhausting port (called first gas exhausting port) connected with anexternal gas suction unit (called first gas suction unit).

According to the powder filling nozzle of the double pipe structure ofthe invention, when the first gas suction unit connected with the firstgas exhausting port provided in the second tubular body is operated, thegas, which is flowing with the powder in the first tubular body, passesthrough the filter material of the first tubular body and is attractedto the first tubular body (not the powder outlet), and a delivery pathspace is formed between the first tubular body and the second tubularbody so that the gas is discharged from the gas exhaust port through thegas delivery path.

Simultaneously, the powder discharged from the first gas exhausting portis attracted around the filter material which is formed on the innerwall of the first tubular body. The plugged state is produced in thefilter material by the powder attracted, and, as a result, the deliveryof the powder in the first tubular body can be stopped instantly.

Thus, even if the plugged state is produced by the powder attracted inthe powder filling nozzle of the present embodiment, there is noundesired influence in the characteristic of powder particles, and evenif the powder is the toner, the toner filling work can be carried outwithout causing the separation of the external additive and thegeneration of the aggregation.

The double pipe structure type powder filling nozzle of the presentembodiment will function effectively when the nozzle is applied to thepreviously described powder filling method. Namely, the powder in thefluidized state is pressurized and discharged by the powder fluidizationunit 10 in FIG. 1 and FIG. 2 passes through the inside of the flowpowder transport pipe 12 with the gas, and it is delivered through theinside of the first tubular body of the powder filling nozzle, and it isdischarged into the container 18.

In this case, the powder filling nozzle is installed so that one openingof the first tubular body that constitutes the powder filling nozzle isconnected to the flow powder transport pipe 12 and the other openingthereof is located near the bottom of the container 18.

Not only the powder but the gas is discharged into the container 18 fromthe inside of the first tubular body, and it is in the state where thepowder and the gas are mixed. The discharged powder is in the state of acomparatively low density within the container when it is filledtherein.

In the case in which the powder is the toner for electrophotographicimage formation, for the efficiency of transportation of the containerproducts filled up with the toner, filling one container with the tonerin a high density state is usually demanded so that the toner can bedischarged smoothly from the container for every image formation withoutcausing change of the toner.

In order to fill the powder into the container in a high density state,the de-aeration work which discharges the gas existing between thepowder particles in the container is usually done. When the double pipestructure type powder filling nozzle of the present embodiment is used,the gas suction nozzle provided separately is used together, the openingof the gas suction nozzle is installed in the powder in the surroundingcondition, and the de-aeration work is performed.

It is preferred that a series of powder filling work is performed asfollows. The work which discharges the powder into the container fromthe powder filling nozzle of the present embodiment is performedinitially. If the suction opening of the gas suction nozzle is in aplugged state with the powder, the de-aeration work will be started. Inthis manner, the discharge of the powder to the container and thede-aeration are performed in parallel temporarily. At the timing thatthe powder in the container is changed into the high-density stateaccording to the given quantity, the stopping of the discharge of thepowder from the powder filling nozzle is performed by operation of thefirst gas suction unit using the function of the powder filling nozzleof the present embodiment.

Although the stopping of the discharge of the powder is performedinstantly, the amount of the powder being discharged can be adjusted byadjusting the suction condition of the first gas suction unit. If thecontainer is filled up with the powder of the given quantity, thecontainer is exchanged with another container. After this, the stoppingof the discharge of the powder is canceled and the filling work iscontinued.

This filling method is applicable to the automation factory where thefilling of the plurality of containers with the powder is performedcontinuously. Moreover, this filling method is also applicable to thefield case in which the service man performs individually the filling ofthe developing device of the customer's image forming device with thetoner directly. The application of the present invention is not limitedto the above-mentioned ones.

However, when two kinds of nozzles: the powder filling nozzle of thedouble pipe structure of the present embodiment and the gas suctionnozzle are used, it is necessary that the container has two loadingslots in which the two nozzles can be inserted separately, or thecontainer has a large loading slot in which the two nozzles can beinserted collectively.

FIG. 5A shows the modification of the powder filling nozzle of doublepipe structure. FIG. 5B is a cross-sectional view of the first tubularbody of the powder filling nozzle of FIG. 5A taken along the line B-B inFIG. 5A.

The powder filling nozzle of FIG. 5A comprises the through holes 53formed in the pipe wall of the tubular body 50 near the end of thetubular body 50, and the gas separation unit 52 (a filter part) providednear the through holes 53 for separating the gas from thefluidized-state powder which is made of the powder particles and the gasbeing delivered through the space c in the tubular body 50.

The enclosure 51 is provided on the outside of the tubular body 50 withsealing nature so that the gas separation unit 53 is surrounded by theenclosure 51. The sealing nature of the space d is maintained bydisposing the sealing member 56 between the pipe walls of the enclosure51 and the tubular body 50.

The enclosure 51 having the sealing nature may be constituted so thatthe enclosure 51 has the opening 54 connected with a gas suction unit(not illustrated).

The powder filling nozzle of the triple pipe structure will be explainedby using an example of the powder filling nozzle used to fill afluidized-state powder into a container which does not meet suchconditions according to the new powder filling method.

The powder filling nozzle of the triple pipe structure according to theinvention is arranged such that another tubular body (called the thirdtubular body) having an inner diameter larger than the outer diameter ofthe second tubular body surround the second tubular body of the powderfilling nozzle of the double pipe structure. Namely, the powder fillingnozzle of the double pipe structure is inserted in and fixed to thethird tubular body.

And the filter part which allows the passing of the gas through thefilter part is disposed in the circumference of the third tubular bodynear the opening of the third tubular body, located on the outlet sideof the first tubular body where the powder is discharged. Further thethird tubular body is provided with a gas exhausting port (called thesecond gas exhausting port) connected with an external gas suction unit(called the second gas suction unit).

The functions of the first tubular body and the second tubular body inthe powder filling nozzle of the triple pipe structure are the same asthose in the case of the powder filling nozzle of the double pipestructure. The powder filling nozzle of the triple pipe structure isarranged so that the opening at one end of the first tubular body isconnected with the flow powder transport pipe and the filter part at theother end of the third tubular body is surrounded by the powder.

When the powder is discharged into the container and the filter part ofthe third tubular body is in a state in which the filter part issurrounded by the powder, the second gas suction unit is operated, thegas existing between the powder particles is attracted and passedthrough the space formed as the gas delivery path between the secondtubular body and the third tubular body, so that the gas is dischargedfrom the second gas exhausting port.

In this manner, according to the powder filling nozzle of the triplepipe structure, the powder can be filled into the container with highdensity, similar to the case in which the powder filling nozzle of thedouble pipe structure is used.

The new powder filling method which is represented by the powder fillingnozzles of the double pipe structure and the triple pipe structuredescribed above, as well as the powder filling device in which thepowder filling nozzle of the invention is provided also constitutes thepresent invention. The powder filling method and device will now beexplained.

As previously, in the new powder filling method which carries out thedelivery of the powder in the fluidized state, it is preferred to makethe powder in the fluidized state uniform by a control unit whichadjusts the introduction gas pressure by the introductory gas controlvalve, adjusts and controls the pressure of the gas in the hermiticallysealed powder fluidization unit (powder logging unit), and introducesthe gas to the powder in the powder fluidization unit (powder loggingunit) uniformly.

By using the uniform gas introduction unit mentioned above, the gas(air) is introduced into the powder fluidization unit gently so that thefluidization of the powder in the required necessary amount can beattained with suppression of the Brownian motion of the powderparticles.

The powder in the fluidized state has a high mobility, and, only if thepressure in the powder fluidization unit is made slightly higher thanthe external pressure, the powder can be discharged out of the powderfluidization unit, and the delivery of the powder through the transferpassage to the end of the powder filling nozzle is smoothly carried out.And the filling of the powder into the container is carried out withoutcausing excessive churning in the container

In the present invention, when the powder filling device is constructedto the structure in which the board made of a sintered resin (productname: “Firutaren”) is interposed between the acrylic cylinder and thebottom flange as a ventilation porous plate, the most suitable result isobtained. Therefore, the case in which the sintered resin board (productname: “Firutaren”) is used to maintain a stable flow state and ahomogeneous powder will be explained below.

Although the Gore-Tex, a sintered metal plate, etc. may be used insteadas a ventilation porous plate, the case in which the sintered resinboard “Firutaren” is used as a ventilation porous plate for such apurpose demonstrates the most uniform air flow.

When fluidizing the powder with the gas and the gas is introduced fromthe outside of the powder fluidization unit only not using the gas ofthe powder fluidization unit, it is important to introduce the gasuniformly. For that purpose, it is preferred to use a gas dispensingunit, such as a fine wire net, which does not produce a large headpressure loss, so that the gas is introduced through the gas dispensingunit.

The control of starting and stopping the filling operation to fill thefluidized-state powder into the container is carried out by regulatingthe pressure open valve provided in the powder fluidization unit toadjust promptly the pressure in the powder fluidization unit. Inaddition, an external pressure unit may be used to help this control.

The powder filling can be operated by changing the pressure in thepowder fluidization unit and/or the powder exhaust passage by the powderflow velocity control valve which is provided independently and issuitable for pressure fine tuning, and the pressure fine tuning to whichthe outflow state of the powder is changed in the middle of the powderfilling operation can also be performed further.

In the present invention, after the powder is fluidized with the gas byswinging the powder storage device enclosed and sealed, the inside ofthe powder storage device can be pressurized. The pressurization of thepowder storage device is performed by decreasing the internal volume ofthe powder storage device using the external pressure. For example, theinternal volume of the powder storage device is decreased by depressingit, the powder is discharged out of the powder storage device, and thepowder is delivered to the end of the powder filling nozzle, so that thepowder is filled into the container.

According to this method, the device for fluidizing the powder can beomitted or the miniaturization of the powder filling device can beachieved.

The powder storage device may have a size and weight so that it can beshaken by the human hands, and may have a size and weight which can beeasily vibrated or rocked with the pump power for pressurization airintroduction.

The powder storage device which is miniaturized can be used also as aconsumable, simple powder filling device by performing the weighing ofthe required quantity beforehand.

The powder in the fluidized state is delivered to the end of the powderfilling nozzle and discharged into the container from the powder fillingnozzle, and the discharging of the powder is stopped instantly by thefunction of the powder filling nozzle of the invention. As describedabove, the amount of discharge of the powder can be adjusted byadjusting the suction pressure with the first gas suction unit.

Moreover, the adjustment of the amount of discharge of the powder canalso be performed by using together the introductory gas control valveof the powder fluidization unit in addition to the powder dischargestopping function of the powder filling nozzle. Thus, it is possible forthe present invention to fill the powder of the given quantity into thecontainer with high density.

Next, the examples of the powder filling nozzle of the invention will beexplained using FIG. 3, FIG. 4A, and FIG. 4B. However, the presentinvention is not limited to these figures. A description will be givenof the example in which the filling of a toner for electrophotographicprinting is performed by using the powder filling nozzle of theinvention, which demonstrates the most suitable result.

FIG. 3 is a cross-sectional view showing an example of the powderfilling nozzle of double pipe structure.

As shown in FIG. 3, the powder filling nozzle of the double pipestructure comprises the first tubular body 30 and the second tubularbody 31, the second tubular body 31 having a length slightly smallerthan the length of the first tubular body 30. The powder in thefluidized state is fed from the opening a of the first tubular body 30,passes along the space c, and is discharged into the container from theopening b.

The through holes 33 are formed near the opening b of the first tubularbody 30 where the powder is discharged. The filter material is woundaround the circumference of the first tubular body 30 to cover thethrough holes 33. The filter part 32 having the quantity of mesh,corresponding to the toner's average-volume particle diameter of 10micrometers or less (which is, for example, a 3500-mesh metallic filteror sintered glass filter) is formed to cover the through holes 33.

The outer diameter of the first tubular body 30 is smaller than theinner diameter of the second tubular body 31. The first tubular body 30is inserted in the second tubular body 31 and arranged so that the spaced is formed between the two tubular bodies, and both ends of the secondtubular body 31 are fixed to the first tubular body 31 so as to closethe space d with the holding materials 35 and 36.

The gas exhausting port 34 which is connected with an external gassuction unit is formed near the end of the second tubular body 31 whichis located on the side of the opening of the first tubular body 30 wherethe powder is flowed in.

When the first gas suction unit is operated, the powder and the gaswhich are delivered in the first tubular body 30 are attracted. The gasis allowed to pass through the filter part 32, and it is delivered alongthe space d and discharged from the gas exhausting port 34. On the otherhand, the powder does not pass through the filter part 32 but isattracted to the filter part 32 provided on the circumference of thefirst tubular body 30, so that the filter part 32 serves to set thethrough holes 33 in a plugged state in which the first tubular body 30is blocked with the powder.

In this way, the delivery of the powder in the first tubular body 30 isstopped instantly.

It is preferred that the gas suction pressure by the first gas suctionunit is in the range of −10 to −60 kPa. And it is more preferred thatthe gas suction pressure is in the range of −30 to −45 kPa.

It is preferred that the powder is delivered while the internal pressureand the delivery speed are adjusted so that the bulk density of thepowder inside the first tubular body 30 is in the range of 0.1 to 0.2.Especially, in order to avoid lowering the powder quality and stop thedelivery of the powder instantly, it is desirable that the suctionpressure by the first gas suction unit is adjusted so that the bulkdensity of the powder when the through holes 33 are set in the pluggedstate is in the range of 0.4 to 0.5.

Next, FIG. 4A is a cross-sectional view showing an example of the powderfilling nozzle of the triple pipe structure.

As shown in FIG. 4A, the powder filling nozzle of the triple pipestructure is constructed such that the third tubular body 37 having theinner diameter larger than the outer diameter of the second tubular body31 is used, and the powder filling nozzle of the double pipe structureis inserted in the third tubular body 37. The space e is formed betweenthe second tubular body 31 and the third tubular body 37, and both endsof the third tubular body 37 are fixed to the second tubular body 31 soas to close the space e with the holding materials 41 and 42.

The through holes 38 are formed near the end of the third tubular body37 on the side of the opening b of the first tubular body 30 where thepowder is discharged. The filter part 39 having the filter materialwhich is wound around the circumference of the third tubular body 37 isformed to cover the through holes 38.

FIG. 4B shows the through holes 38 provided above the first tubular body30.

As shown in FIG. 4B, the gas exhausting port 40 which is connected witha second external gas suction unit is provided near the end of the thirdtubular body 37 on the side of the opening a of the first tubular body30 where the powder is flowed in.

The functions and composition of the first tubular body 30 and thesecond tubular body 31 in the powder filling nozzle of the triple pipestructure are the same as those in the powder filling nozzle of thedouble pipe structure.

In the powder filling nozzle of the triple pipe structure, when thesecond gas suction unit is operated, the powder and the gas which aredischarged in the container are attracted. The gas is allowed to passthrough the filter part 39, and it is delivered along the space e anddischarged from the gas exhausting port 40. On the other hand, thepowder remains without passing through the filter part 39, and it isfinally filled into the container with a high-density state.

It is preferred that the gas suction pressure by the second gas suctionunit is in the range of −10 to −60 kPa. And it is more preferred thatthe gas suction process is in the range of −20 to −35 kPa.

The first tubular body, the second tubular body, and the third tubularbody which constitute the powder filling nozzle will be explained.

For each of these tubular bodies, a long pipe type is usually used. Eachtubular body may be made of a metal, such as stainless steel, titaniumand aluminum, or made of a plastic material.

The length of each tubular body is not restricted to a specific length.However, it is usually preferred that the first tubular body is thelongest one, the second tubular body is the second longest one, and thethird tubular body is the shortest one. This feature is desired for thesake of functionality and processability of the powder filling nozzle.

If the desired function is demonstrated, the thickness of each tubularbody is not restricted to a specific thickness. However, it is preferredthat the outer diameter of the first tubular body is in the range of 4to 20 mm.

Especially the length and thickness of each of the first tubular body,the second tubular body, and the third tubular body, and the space widthformed between these tubular bodies are important elements in order todemonstrate the functions of the powder filling nozzle of the presentinvention. It is preferred that the following conditions (1) to (5) aresatisfied simultaneously:

(1) The outer diameter of the first tubular body/the length of the firsttubular body: 65-85;

(2) The outer diameter of the second tubular body/the length of thesecond tubular body: 55-75;

(3) The outer diameter of the third tubular body/the length of the thirdtubular body: 40-46;

(4) The outer diameter of the first tubular body/the inner diameter ofthe second tubular body: 1.05-1.3; and

(5) The outer diameter of the second tubular body/the inner diameter ofthe third tubular body: 1.08-1.5.

The filter part which is provided for the powder flow stopping isdisposed on the circumference of the first tubular body in theneighborhood of the outlet of the first tubular body in the powderfilling nozzle of the invention.

The term “neighborhood”, which indicates the location where the filterpart is disposed, means that, in order to sufficiently achieve thefunction of stopping the powder discharging flow in the first tubularbody, it is desired to dispose the filter part at a location which isnot exactly the same as the outlet of the first tubular body. It ispreferred to dispose the filter part at a location which is distant fromthe outlet in the range of 5 to 25 mm.

It is preferred that the width of the filter part is more than 0.3 timesthe inner diameter of the powder discharge outlet opening of the firsttubular body. Specifically, it is preferred that the width of the filterpart is in the range of 4 to 20 mm.

Next, the two methods of forming the filter part will be explained.

One method is as shown in FIG. 3 and FIG. 4A. According to this method,the through holes are formed in the first tubular body near the endthereof used as the outlet of the first tubular body, and the filtermaterial is wound around the circumference of the first tubular bodywhere the through are formed to cover the through holes. In this manner,the filter part is formed.

This method is to form the through holes in the first tubular bodyitself, and it is aimed at obtaining good operability of the nozzle withthe straightness, toughness of the nozzle, processability of winding thefilter material, etc.

The size of the through holes is not restricted to a specific size.However, it is preferred that the size of the through holes is less than⅔ of the inner diameter of the first tubular body. It is preferred toprovide two or more through holes in a row in the length direction ofthe tubular body. And it is more preferred to provide the through holesin the length direction of the tubular body in two or more rows and twoor more columns.

The other method is that the first tubular body is made from a tubularbody having a lamination structure in which a tubular member made of afilter material and a tubular member made of a non-filter material arebonded together, and the tubular member of the filter material is madeto serve as the filter part. This method is aimed at reducing theclogging of the powder in the filter part.

It is essentially necessary that the filter part allows only the gas topass through the filter part but does not pass the powder, when it isattracted by the gas suction unit. The filter material of the filterpart is not restricted if this function is demonstrated.

As the filter material, it is important to select the mesh filtermaterial. A lamination object in which different filter materials of twoor more kinds of the mesh are laminated can be used as the filtermaterial. It is preferred that the lamination object is comprised of acoarse-mesh filter material on the outside, and a fine-mesh filtermaterial on the inside. The use of this lamination object is preferablyapplicable to the latter method mentioned above, which shows acomparatively low toughness of the filter part.

When compared with the filter part made of a plain weave filtermaterial, the filter part made of a twill-weave filter material has asmaller filtration particle size and a higher surface smoothness. Thefilter part made of a twill-weave filter material is more suitable forthe gas separating unit in the powder filling nozzle of the inventionpass, because it demonstrates the function of the filter material thatallows the gas to pass through the filter part but does not allow thepowder to pass through the filter part.

It is preferred to select the thickness of the filter material inconsideration of the narrow space formed between the first tubular bodyand the second tubular body.

In the powder filling nozzle of the triple pipe structure of theinvention, a filter part for gas suction is disposed on thecircumference of the third tubular body in the neighborhood of theoutlet of the powder filling nozzle where the powder is discharged.

The term “neighborhood”, which indicates the location where the filterpart is disposed, means that, in order to sufficiently achieve thefunction of gas suction of the container inside, it is desired todispose the filter part at a location which is exactly the same as theoutlet of the powder filling nozzle. It is preferred to dispose thefilter part at a location which is distant from the outlet in the rangeof 5 to 15 mm.

Since it is necessary to discharge a lot of gas, it is preferred thatthe width of the filter part is larger than the width of the filter partof the first tubular body, and it is preferred that the width of thefilter part concerned is in the range of 50 to 150 mm.

The formation method and material of this filter part are essentiallythe same as those in the case of the first tubular body.

The first tubular body is differed from and it is a filter part. Whenfollowing the method of providing and forming a through hole in thetubular body itself, as for a through hole, it is preferred that thepath is ⅔ or less of the inner diameter of the third tubular body, andit is preferred to provide two or more rows of desirable still suchproviding in the machine direction of the tubular body in four or morerows and four or more columns.

As for the position which is provided in each of the second tubular bodythat constitutes the powder filling nozzle of the present invention, andthe third tubular body and in which the first gas exhausting port andthe second gas exhausting port are provided, it is preferred that theyarrange and install near where the fluidized-state powder of the firsttubular body flows in the opening although both sides are notrestrictive.

The diameter of the powder discharge outlet for both the cases is notrestricted to a specific diameter. However, it is preferred that thediameter of the powder discharge outlet is in the range of 4 to 7 mm.

Each of the gas suction units which are connected to the first gasexhausting port and the second gas exhausting port, respectively may beof a vacuum pump suction type, an ejector mechanism suction type, etc.Among them, the ejector mechanism suction type is more suitable since ithardly needs maintenance.

The holding materials for preventing gas leakage and fixing the spaceformed between the ends of the second tubular body near the end of thefirst tubular body, and the space formed between the ends of the thirdtubular body near the end of the second tubular body, may be made of aring shape holding material, a binding material, solder, etc.

Next, the powder filling device of the invention in which theabove-described powder filling nozzle of the triple pipe structures isprovided will be explained using FIG. 1 and FIG. 2. However, the powderfilling device of the invention is not limited to these figures.

In a case where the powder filling device of the invention isconstructed with the powder filling nozzle of the double pipe structurewhich is not illustrated, two separate gas suction nozzles are prepared,and the two nozzles are respectively inserted in a container having twoloading slots or collectively inserted in a container having a largerloading slot provided to receive both the two nozzles.

In the powder filling device of FIG. 1 and FIG. 2, the elements in FIG.2 which are the same as corresponding elements in FIG. 1 are designatedby the same reference numerals and have the same meaning.

In the powder filling device shown in FIG. 1 and FIG. 2, the powderfluidization unit 10 with which the air introductory part is disposed onthe bottom for powder fluidization is provided. In the powderfluidization unit 10, the powder delivery tube 24 is insertedbeforehand, and one end of the powder delivery tube 24 is connected withthe flow powder transport pipe 12, and the end of the flow powdertransport pipe 12 which is not connected with the powder delivery tube24 is connected with the powder filling nozzle 17 of the triple pipestructure of the invention.

The end of the powder filling nozzle 17 on the side where it is notconnected with the flow powder transport pipe 12 is inserted in theinside of the container 18 for powder filling so that it does notcontact the bottom of the container 18.

The air header 3 has some resistance to the pressure such that the airheader 3 is capable of increasing the internal pressure of the powderfluidization unit 10. The air header 3 is provided with the thirdpressure gauge p3.

The first reducing valve 25, the second reducing valve 26, and the airflow meter 27 are disposed in this order in the compressed air piping 7linked to the air header 3. The first pressure gauge p1 is disposedbetween the first reducing valve 25 and the second reducing valve 26,and the second pressure gauge p2 is disposed between the second reducingvalve 26 and the air flow meter 27, respectively.

When the powder filling device is set to work, the powder which is beingfilled into the container is first loaded in the powder fluidizationunit 10 from the powder entrance slot 11 with the closing valve, and thepressure open valve 13 for opening and closing the internal pressure isopened.

On the other hand, operation of the powder flow velocity control valve15 for pressure tuning may be automated with an electromagnetic valve orperformed by the human power.

After the powder is loaded, the pressure open valve 13 is closed, andthe gas is introduced from the vent pipe 7 into the air header 3 whichis a pressurization accumulator as the gas introducing unit. Theincoming flow of the gas may be adjusted by the first reducing valve 25and the second reducing valve 26 which serve as the pressure regulationand flow rate adjustment unit. During operation, the incoming flow ofthe gas is continued. The introduced gas is passed through theventilation porous plate 2 and distributed in the powder uniformly, sothat the powder is fluidized with the introduced gas.

The introduced gas is uniformly distributed in the powder by theventilation porous plate 2, and the powder is fluidized with the gas.While the pressure open valve 13 is closed, the fluidized-stated powderis extruded to the powder transport pipe 12 from the inside of thepowder fluidization unit 10 by the pressure of the gas which is used forthe fluidization. The powder is discharged into the container 18 fromthe end of the powder filling nozzle 17 of the invention inserted in theinside of the container 18.

The end of the powder filling nozzle 17 is inserted in the container sothat it does not contact the bottom of the container. The vent pipe 7may be made of a flexible material and the length of the vent pipe 7 isnot limited if it exhibits the intended function. Thus, the powderfluidization unit 10 and the container 18 can be arranged at separatelocations which are distant from each other.

The flow powder transport pipe 12 may be made of a flexible material andthe length of the flow powder transport pipe 12 is not limited if onlyit exhibits the intended function. Thus, the powder fluidization unit 10and the container 18 can be arranged at separate locations which aredistant from each other.

In the container, a lot of gas is discharged together with the powder,and the inside of the container is mostly divided into the upper layerpart in which only the gas exists and the lower layer part in which thepowder and the gas are mixed.

In order to discharge the gas of the upper layer part, the lid memberattached to the inlet part of the container 18 is provided with at leastthe powder-gas separation screen (ventilation porous plate) 16. The gasof the upper layer part is discharged from this vent hole, and thepressure in the container is adjusted.

The lid member has a size that can fit into the opening of the containerfor powder filling, is made of a ventilation porous material, and has ahole for inserting the powder filling nozzle. The lid member thecircumference of which is surrounded by an elastic packing may be usedto increase the fitting characteristic.

In the case of the powder filling nozzle of the triple pipe structure,the de-aeration about the gas existing between the powder particles ofthe lower layer part is performed by operation of the second gas suctionunit which is externally disposed and connected with the second gasexhausting port provided in the third tubular body.

In the case of the powder filling nozzle of the double pipe structure,the de-aeration is performed by operation of the second gas suction unitusing the gas suction nozzle inserted into the powder in the containeras disclosed in Japanese Laid-Open Patent Application No. 2001-31002.

In the powder filling device of FIG. 1 and FIG. 2, at the beginning offilling when the inside of the container 18 for powder filling iscompletely empty, the degree of opening and closing of the powder flowvelocity control valve 15 of the powder fluidization unit 10 isadjusted, so that the powder discharge speed from the powderfluidization unit 10 is initially decreased. Thus, the irregularity ordiffusion inside the container 18 in which the fluidized-state powder isfilled is avoided.

Next, after the quantity of the fine powder particle clouds staying inthe container 18 increases so that it is surrounded mostly by thefluidized-state powder flow discharged from the end of the powderfilling nozzle 17, the powder flow velocity control valve 15 is adjustedto an increased opening position and the filling operation is continued.

The filling nozzle 17 is put on the filling port upper part of container18 for powder filling, may be automatically inserted in container 18inside for powder filling after the set of container 18 for powderfilling, or may be inserted manually.

Alternatively, another method may be used in which the lid member isplaced on the top of the powder filling nozzle to be fixed in the statewhere it is inserted in the hole, near the connection part of the flowpowder transport pipe and the filling nozzle, to attach the container tothe lid member, to exchange the container after powder filling, and tofill up many containers with the powder one by one.

The lid member may be removed from the container when the container isfilled and delivery stopped.

And working the first gas suction unit connected with the first tubularbody that constitutes the powder filling nozzle of the triple pipestructure, although not illustrated, the delivery of the powder into theinside of the first tubular body is stopped, and the discharge of thepowder into the container can be stopped.

The stopping of the powder discharge can also be performed while theopening of the pressure open valve 13 of the powder fluidization unit 10and the operation of the gas suction unit are performed in parallel. Ifthe pressure open valve 13 is opened somewhat so that the internalpressure in the powder fluidization unit 10 used as the powder transportforce is reduced, the powder delivery stopping can be performedeffectively.

In the powder filling device 1 of FIG. 2, the ventilation porous plate 2(a sintered metal plate, a sintered resin board, a fine-tooth wire net,etc.) is detachably attached via the flange to the lower part of thepowder fluidization unit 10 made of a flexible material, such as aflexible plastic, and the air may pass through the ventilation porousplate 2 for forming the fluidized state powder flow.

Moreover, the powder filling device 1 of FIG. 2 further comprises thecompressed air piping as the vent pipe 7, the air header 3 as the gasintroducing unit with the vent pipe 7 being detachably attached, thepowder entrance slot 11 with the closing valve, the pressure open valve13 for opening and sealing of the internal pressure, the powder flowvelocity control valve 15 for pressure fine tuning, the stainless steelpipe as the flow powder delivery tube 24, and the urethane inner tube asthe exhaust passage (transfer passage) 12 which is detachably attached.The gas powder separation screen 16 having a diameter that can be fittedto the mouth part of the container 18 is provided on the base of thepowder filling nozzle 17 made of the stainless steel and detachablyattached to the exhaust passage 12 (urethane tube).

In this example, the gas powder separation screen 16 has thecircumference which is surrounded by the elastic packing 19 which ismade of a polypropylene ring in the shape of a truncated cone.

However, unlike the powder filling device of FIG. 1, the powder fillingdevice of FIG. 2 has the check valve 8 disposed at the gas outlet as agas introducing unit, and the pump 6 provided to supply the air to theair header 3. The pump 6 is made in the bellows structure which isexpanded and contracted by the small electric motor 5.

The pump 6 is detachably fixed in the holding frame 9. When the pump 6is expanded and contracted by the small electric motor 5, the powderfluidization unit 10 is vibrated through the holding frame 9, so thatthe powder in the powder fluidization unit 10 is fluidized with the gasby this vibration.

In the powder filling device of FIG. 2, it is not necessary to constructthe powder fluidization unit 10 and the air header 3 by a thickmaterial, and the weight saving and miniaturization of the whole devicecan be promoted further. The powder filling device can be operated onlyby inserting the plug 21 for power supply of the small electric motor 5into the electric socket provided in the copying machine.

The powder filling device needs little power consumption when comparedwith the case of the auger-type filling device which is conventionallyused, and it can be operated with 100V power supply for home use, notwith 200V power supply for industrial use.

However, if it usually depends only on the electric power, as areduction level of an environmental impact, there is not a greatdifference between the 100V case and the 200V case. Then, using naturalpower sources as the source of power for working the powder fillingdevice is also set to one embodiment of the present invention.

The electric energy as used in the present invention means the electricpower supplied to the office, the home, etc. with the power supply linefrom the electric power company.

On the other hand, natural power sources mean the electric power otherthan the electric power built in the electric power company, and is madefrom its own house, and, specifically, have pointed out the electricpower obtained by sunlight energy (solar-powered electricity generation)and wind power energy (wind power exothermic system).

Natural power sources are the sunlight energy and wind power energywhich can be obtained concrete anywhere, and the geothermal energy whichcannot be obtained easily is excepted.

For example, the conversion of the sunlight energy to the electricalenergy is carried out using a solar cell as follows. In this solar cell,the light from the sun is irradiated to the connection part of theconnection of the p-type semiconductor and the n type semiconductor,such as silicon, and the electrical energy of direct current isoutputted from the semiconductor solar cell.

The conversion of the wind power energy to the electrical energy iscarried out as follows. For example, 1-3 wind vanes are rotated with thewind force, this rotation is transmitted to the rotary coil arrangedbetween the N pole and the S pole, and the d.c. or a.c. current isobtained.

Suppose that the sunlight electrode unit and the two wind turbinegenerators are prepared. The electric generating capacity of sunlight is3 kW, the electric generating capacity of one of the two wind turbinegenerators is 60 W, and the electric generating capacity of the otherwind turbine generator is 72 W.

Using the powder filling nozzle and the sunlight electrode unit and thetwo wind turbine generators, the powder is filled into 100 tonercontainers (the capacity is 1560 ml), and the results of filling thetoner containers with the powder in summer and in winter are comparedwith the normal case in which only the commercial electric power 100V isused without using the natural power source as follows.

Powder filling in summer: minimum temperature 20 degrees C., maximumtemperature 35 degrees C., average wind speed 5 m/s, weather fine.

Powder filling in winter: minimum temperature 5 degrees C., maximumtemperature 15 degrees C., average wind speed 10 m/s, weather cloudy.

In the case of the summer time powder filling, the amount of thecommercial electric power used is one fifth of that in the normal case.In the case of the winter time powder filling, the amount of thecommercial electric power used is one third of that in the normal case.The amount of carbon dioxide generated is ⅕ or less of that in thenormal case in which only the commercial electric power 100V is used,and the influence to the environment is remarkably reduced.

In another embodiment of the powder filling device of the inventionwhich is not illustrated, the powder is mixed the gas and fluidized, andthe container is made from a flexible plastic material, such aspolyethylene, which is capable of being deformed easily by the humanpower, and the container is formed into an airtight container with onepiping connection mouth. The external pressure is applied so that theplastic container is deformed, and the internal pressure is increasedusing the urethane inner tube connected to the piping connection mouth.The powder may be distributed to the bottom of the container using theurethane inner tube.

Alternatively, at least two piping connection mouths are provided in anon-deformable container which is made of a rigid plastic. And thepiping of the compressed air of 0.2 MPa or less is connected to one ofthe connection mouths of the container, and the other connection mouthserves as a powder transport pipe, and the powder is supplied to thecontainer bottom through the inner tube.

As the source of the compressed air, not only the usual compressor butalso the inflator of manual operation for a bicycle may be used.

As described above, the powder may be discharged from the powderfluidization unit 10 to the powder filling nozzle 17 by raising thepressure in the powder fluidization unit 10. Alternatively, the same maybe carried out by applying the external pressure to the powderfluidization unit 10 and decreasing the internal volume of the powderfluidization unit 10.

The powder for use in the powder filling device and powder fillingnozzle of the invention is not restricted to a specific powder. However,it is effective if it is applied to the toner for electrostatic latentimage development regardless of the toner kind. It is possible toeffectively use the toner whose average particle diameter is in therange of 0.2 to 20 micrometers, in the range of 5 to 15 micrometers, andin the range of 7 to 12 micrometers.

The container 18 applied to the present powder filling device for powderfilling is not restricted. For example, the container forelectrophotographic image formation of a bottle or cartridge type whichis made of a resin, such as polyethylene or polyester can be suitablyused.

The container configuration may be various, such as a cylinder type, apolygon, and other configurations. For example, when a cylinder typecontainer is used, the diameter of the container may be in the range of10 to 300 mm, and the length of the container may be in the range of 50to 2000 mm.

Next, the results of the experiments which are performed according tothe powder filling methods of the respective embodiments in which thepowder filling nozzle of the invention is used and according to thecomparative examples will be described. However, the present inventionis not limited by this case of the operation.

(1) The Check of the Powder Delivery Stopping Function of the PowderFilling Nozzle of the Present Invention

The powder filling device used for the experiment will be explainedbased on the powder filling device 1 shown in FIG. 1 and FIG. 2.

The powder fluidization unit 10 used for the experiment has a generallycylindrical configuration with the capacity of 200 liters. The powderfluidization unit 10 is provided at the bottom with the ventilationporous plate 2 which is made of a porous plate-like resin material withthe void diameter of 10 micrometers, the porosity of 30%, and thethickness of 5 mm.

The powder delivery tube 24 in the powder fluidization unit 10 and theend of the powder filling nozzle of double pipe structure are connectedtogether via the flow powder transport pipe 12. The powder fillingnozzle is passed through the hole provided in the lid member includingthe ventilation porous plate 16 made of resin, and inserted into thepowder storage container 18.

The container of the toner powder used for the experiment is made of apolyester resin, and this container has the interval volume of about1560 cc, the diameter of about 100 mm, and the length of about 200 mm,and the opening where the powder filling nozzle is inserted has thediameter of about 20 mm.

(2) Discharge of the Toner to the Container

As a toner powder, the Type 8000 toner or Ricoh color laser printers(the average volume particle diameter: 7 micrometers and the specificgravity: 1.2) is prepared, and the 60 kg of toner is fed into the powderfluidization unit 10 from the powder entrance slot 11 in the powderfluidization unit 10 while the powder flow velocity control valve 15 isadjusted.

Next, while the pressure open valve 13 provided near the powder entranceslot 11 of the powder fluidization unit 10 is adjusted, the deliverypressure is adjusted through the two steps of reducing valves: the firstreducing valve 25 and the second reducing valve 26 from the compressedair source. The air is delivered to the air header 3 for 5 minutes at arate of 30 liters per minute. The powder layer and the air layer in thepowder fluidization unit 10 are balanced, the upper powder surface ismade in a still state, and the fluidized state of the toner powder isformed.

The air pressure is impressed so that the internal pressure of thecontainer is set to 15 kPa, the toner powder in the powder fluidizationunit 10 is changed into the state where the powder filling nozzle issurrounded by the toner powder, and the toner powder is dischargedthrough the powder filling nozzle 17 into the container 18.

Next, the subsequent operations in the following items (3) to (6) willbe explained.

(3) The Stopping of the Toner Powder Discharge at the Time of Using thePowder Filling Nozzle (Indicated in the Following Items (4) and (5)) ofthe Present Invention

Using the powder filling nozzle of this invention, the toner powder isdischarged into the powder container as in the above item (2), and theweight of the container 18 is measured beforehand by the balance (theload cell 6 kgf). When the discharge toner powder reaches thepredetermined weight, the gas suction unit is operated so that thesuction pressure is set to −20 kPa. While the air is discharged, theoutlet of the nozzle is closed and the discharge of toner is stoppedinstantly.

(4) The Powder Filling Nozzle of the Double Pipe Structure for Use inthe Experiment (see FIG. 3)

The first tubular body 30 that constitutes this nozzle of the doublepipe structure is made of a stainless steel pipe having a length ofabout 400 mm, a inner diameter of 6 mm, and an outer diameter of 7 mm.At the position of 5 mm apart from the end of the steel pipe, and at theposition of 12 mm therefrom, and further at the positions in theintersecting direction (the total of eight places) there are formed thethrough holes 33 each having a diameter of 3 mm, respectively. Astainless steel mesh (made of a twill-weave filter material, 500/3500)is attached to the portion having a width of about 10 mm, so that thefilter part 32 is formed in the surroundings of the through holes andthe through holes are covered with the stainless steel mesh.

The second tubular body 31 is made of a stainless steel pipe having alength of about 450 mm, a inner diameter of 8 mm, and an outer diameterof 9 mm, the first gas exhausting port 34 is prepared near the end ofthe steel pipe, and both the ends of the steel pipe are soldered (Sn—Pballoy) after the first tubular body 30 is inserted in the second tubularbody 31. In this manner, the double pipe structure nozzle is formed.

The first gas exhausting port 34 is connected with the first gas suctionunit (the product ME-60 from Koganei Co.) which is prepared separately.

(5) The Powder Filling Nozzle of the Triple Pipe Structure for Use inthe Experiment (see FIG. 4)

The first tubular body 30 and the second tubular body 31 that constitutethe nozzle of the triple pipe structure are the same as those of thedouble pipe structure nozzle of the item 5 above, the sealing and fixingof the ends of the nozzle is similarly carried out by soldering (Sn—Pballoy).

The third tubular body 37 is made of a stainless steel pipe having alength of about 500 mm, a inner diameter of 11 mm, and an outer diameterof 12 mm. The through holes 38 each having a diameter of 5 mm are formedin the total of 11 places by the pitch of 8 mm from the position of 15mm apart from the end of the stainless pipe, respectively. Moreover, thethrough holes 38 each having a diameter of 5 mm are formed in the totalof ten places by the pitch of 8 mm in the intersecting direction fromthe position of 19 mm apart from the end of the stainless pipe,respectively is prepared.

A stainless steel mesh (made of a twill-weave filter material, 500/3500)is attached to the portion having a width of about 100 mm, so that thefilter part 39 is formed in the surroundings of the through holes andthe through holes are covered with the stainless steel mesh. The secondgas exhausting port 40 is formed near the end of the pipe.

After the first tubular body 30 is inserted into and the second tubularbody 31, the sealing and fixing of the ends of the third tubular body 37is carried out by soldering (Sn—Pb alloy). In this manner, the triplepipe structure nozzle is formed.

The second gas exhausting port 40 is connected with the second gassuction unit (the product ME-60 from Koganei Co.) which is preparedseparately.

(6) The Stopping of the Toner Powder Discharge at the Time of Using thePowder Filling Nozzle for Comparison

The filling nozzle for comparison is made of a stainless steel pipehaving a length of about 400 mm, a inner diameter of 6 mm, and an outerdiameter of 7 mm.

Using this filling nozzle for comparison, a toner powder is dischargedby the powder container as in the item 2 above, and the weight of thecontainer 18 is measured beforehand by the balance (the load cell 6kgf).

The impression of air pressure is stopped by the introductory gascontrol valve 20 provided in the powder fluidization unit 10, when theweight of the discharge toner powder reaches the predetermined weight.At the same time, the pressure supply of the powder fluidization unit 10is turned ON by the pressure open valve 13, so that the pressure isbalanced with the atmospheric pressure. However, the discharge of toneris not able to be stopped instantly.

(7) Comparative Evaluation of the Powder Delivery Stopping Function ofthe Powder Filling Nozzle

When the powder filling nozzle of the double pipe structure is used, theseries of the above operations related to the toner powder discharge tothe container is carried out. Such is performed for the case of theembodiment 1 in which the powder filling nozzle of the double pipestructure is used, the case of the embodiment 2 in which the powderfilling nozzle of the triple pipe structure is used, and the case of thecomparative example 1 in which the powder filling nozzle for comparisonis used. As for the toners of the four colors: cyan, magenta, yellow,and black, which constitute the Type 8000 toner for use in Ricoh colorlaser printers, the experiment is repeatedly carried out for 100containers (the total of 400), the accuracy of the filling amount ischecked based on the ratio of the lacking amount to the target fillingamount of each toner powder in the container by using the standarddeviation. In this manner, the powder delivery stopping function isevaluated.

The results are shown in FIG. 6 (3σ (sigma) denotes the fillingaccuracy; sigma: standard deviation (±3σ corresponds to the probabilityof 99.6%)).

When the target filling amount is set to 275 g and 550 g, the amount oflacking is 1.1-1.5 g and 2.2-2.3 g in the case of the embodiment 1 andthe case of the embodiment 2, respectively, while it is 11.5-14.2 g and24 g, in the case of the comparative example. It is apparent from FIG. 6that the powder filling nozzle of the present invention has an excellentpowder delivery stopping function in comparison with the comparativeexample.

(Check of the High-Density Filling Function of the Triple Pipe StructureFilling Nozzle of the Invention)

(1) High-Density Powder Filling of the Triple Pipe Structure FillingNozzle

While discharging the toner powder into the container as in the aboveitem (1) using the triple pipe structure filling nozzle, the second gassuction unit is operated so that the suction pressure is set to −30 kPa.Only the air is sucked and discharged from the nozzle which issurrounded by the toner powder, the nozzle is raised while the tonerpowder capacity is decreased, and the high-density state of the tonerpowder is formed within the container.

(2) Comparative Evaluation of the High-Density Powder Filling Functionof the Powder Filling Nozzle

The case in which the bulk density of the toner powder in the containeris changed into a high-density state using the triple pipe structurefilling nozzle of the above item (1) (case 1), and the case in whichonly the toner powder is discharged in the container using the triplepipe structure filling nozzle in the above item (1) (case 2) arecompared. About the toners of four colors (cyan, magenta, yellow, black)which constitute the Type 8000 toner for Ricoh color laser printers, theexperiment is carried out repeatedly on 100 containers (the total of400), and the measurements of them are collected respectively, and theaverage value of the measured value for the 100 containers is computed.

The measurement of bulk density is performed using the mark whichindicates the toner capacity in the container, and the mark whichindicates the capacity level immediately after the filling is done. Thebulk density is computed from the weight of the filling toner powder andthe capacity. And the mark which indicates the capacity of the containeris put using the water measured with the measuring cylinder.

The results are shown in FIG. 7. It is apparent from FIG. 7 that thetriple pipe structure filling nozzle of the present invention provides ahigh-density filling function enough.

(3) Comparative Evaluation of the Filling Method by the Filling Time

The time required for discharging of the toner powder into the containerusing the powder filling nozzle of double pipe structure, and the powderfilling nozzle for comparison as in the above item (1), making itsediment as it is, and filling up (the case of the embodiment 1 and thecase of the comparative example), and after discharging the toner powderin the container using the powder filling nozzle of the triple pipestructure, the time required for attracting air and filling up (the caseof the embodiment 2) are measured.

With respect to the black toner, the experiment is repeated performedfor 100 containers (550 g/each), and the average filling time ismeasured.

As a result, the time in the case of the embodiment 1 is 35.1 seconds,while the time in the case of the comparative example is 41.8 seconds.The time in the case of the embodiment 2 is 18.5 seconds. Thus, it isconfirmed that if the triple pipe structure filling nozzle of theinvention is used, not only the powder delivery stopping function butalso the high-density filling function is realized. Moreover, the triplepipe structure filling nozzle of the invention is effective inshortening of the filling time.

As described in the foregoing, according to the present invention, thepowder filling nozzle, powder filling device, and powder filling methodwhich make it possible to fill up the container with the powder of agiven amount in a high-density state efficiently and precisely. That is,the flow state of the powder which introduced gas uniformly into thepowder and is controlled by the minimum quantity of gas is acquired, aflow powder is flowed into the back or the bottom of a small-inletfilling container or a complicated-shaped filling container, and highdensity and the method of filling up with a non-particulate can beoffered easily.

1. A powder filling nozzle used for filling up a container with a powdermixed with a gas and in a fluidized state, comprising: a tubular bodyhaving an opening for discharging the powder in the fluidized state intothe container; and a gas separating unit disposed near the opening ofthe tubular body and allowing the gas delivered together with the powderin the tubular body to pass through the gas separating unit but notallowing the powder to pass through the gas separating unit, wherein thegas separating unit serves to set the opening in a plugged state by thepowder separated from the gas, so that the delivery of the powder fromthe tubular body into the container is stopped, wherein the tubular bodyhas a double pipe structure including a first tubular body and a secondtubular body, the first tubular body being inserted into the secondtubular body so that a gap between the two tubular bodies is formed as agas delivery path, both ends of the second tubular body being fixed tothe first tubular body so as to close the gap, the first tubular bodyserving as a delivery path which discharges the powder in the fluidizedstate fed from one opening of the first tubular body into the containerthrough the other opening of the first tubular body, the gas separatingunit including a first filter part which does not pass the powdertherethrough but allows the gas to pass therethrough, the second tubularbody having a gas exhausting port connected with an external gas suctionunit, and the second tubular body having a function of discharging thegas, passing through the first filter part and being attracted to thefirst tubular body by operation of the external gas suction unit, fromthe gas exhausting port through the gas delivery path, and wherein thetubular body has a triple pipe structure including a third tubular bodyin addition to the first and second tubular bodies, the third tubularbody having an inner diameter larger than an outer diameter of thesecond tubular body, the second tubular body being inserted into thethird tubular body so that a gap between the second and third tubularbodies is formed as a second gas delivery path, both ends of the thirdtubular body being fixed to the second tubular body so as to close thegap between the second and third tubular bodies at both ends thereof,the third tubular body including a second filter part at an outercircumference thereof, the third tubular body having a second gasexhausting port connected with a second external gas suction unit, andthe third tubular body having a function of attracting through thesecond filter part the gas, existing in the powder discharged into thecontainer, by operation of the second gas suction unit, and having afunction of discharging the gas, passing through the second deliverypath between the second tubular body and the third tubular body, fromthe second gas exhausting port.
 2. The powder filling nozzle of claim 1wherein the opening of the tubular body is constituted by a through holewhich is formed in the first tubular body, and the gas separating unitincludes the first filter part which is provided on a circumference ofthe first tubular body so that the through hole is covered with thefilter part.
 3. The powder filling nozzle of claim 1 wherein the firsttubular body has a lamination structure in which a tubular member of afilter material and a tubular member of a non-filter material arebonded, and the tubular member of the filter material serves as thefirst filter part.
 4. The powder filling nozzle of claim 2 wherein thefirst filter part is made of a twill-weave filter material.
 5. Thepowder filling nozzle of claim 3 wherein the first filter part includesa laminated member made of two or more filter materials with differentmeshes.
 6. The powder filling nozzle of claim 5 wherein the laminatedmember has a fine-mesh filter material at an inner core portion of thefirst tubular body.
 7. The powder filling nozzle of claim 1 wherein awidth of the first filter part is larger than 0.3 times an innerdiameter of the opening of the first tubular body.
 8. A powder fillingdevice including a hermitically sealed powder fluidization unit and apowder filling nozzle, the powder filling device filling a powder, mixedwith a gas and changed to a fluidized state by the powder fluidizationunit, into a container through a delivery path by using the powderfilling nozzle, the powder filling nozzle comprising: a tubular bodyhaving an opening for discharging the powder in the fluidized state intothe container; and a gas separating unit disposed near the opening ofthe tubular body and allowing the gas delivered together with the powderin the tubular body to pass through the gas separating unit but notallowing the powder to pass through the gas separating unit, wherein thegas separating unit serves to set the opening in a plugged state by thepowder separated from the gas, so that the delivery of the powder fromthe tubular body into the container is stopped, wherein the tubular bodyhas a double pipe structure including a first tubular body and a secondtubular body, the first tubular body being inserted into the secondtubular body so that a gap between the two tubular bodies is formed as agas delivery path, both ends of the second tubular body being fixed tothe first tubular body so as to close the gap, the first tubular bodyserving as a delivery path which discharges the powder in the fluidizedstate fed from one opening of the first tubular body into the containerthrough the other opening of the first tubular body, the gas separatingunit including a first filter part which does not pass the powdertherethrough but allows the gas to pass therethrough, the second tubularbody having a gas exhausting port connected with an external gas suctionunit, and the second tubular body having a function of discharging thegas, passing through the first filter part and being attracted to thefirst tubular body by operation of the external gas suction unit, fromthe gas exhausting port through the gas delivery path, and wherein thetubular body has a triple pipe structure including a third tubular bodyin addition to the first and second tubular bodies, the third tubularbody having an inner diameter larger than an outer diameter of thesecond tubular body, the second tubular body being inserted into thethird tubular body so that a gap between the second and third tubularbodies is formed as a second gas delivery path, both ends of the thirdtubular body being fixed to the second tubular body so as to close thegap between the second and third tubular bodies at both ends thereof,the third tubular body including a second filter part at an outercircumference thereof, the third tubular body having a second gasexhausting port connected with a second external gas suction unit, andthe third tubular body having a function of attracting through thesecond filter part the gas, existing in the powder discharged into thecontainer, by operation of the second gas suction unit, and having afunction of discharging the gas, passing through the second deliverypath between the second tubular body and the third tubular body, fromthe second gas exhausting port.
 9. The powder filling device of claim 8wherein the powder filling device works with an electric power obtainedfrom at least one of natural power sources including a sunlight energyand a wind power energy and used as a source of power.
 10. The powderfilling device of claim 8 wherein a lid member which is made of aventilation porous material and includes a hole for inserting the powderfilling nozzle therein is fitted into an opening of the container in astate in which the powder filling nozzle is inserted in the hole of thelid member.
 11. The powder filling device of claim 8 wherein the powderfluidization unit has an introductory gas control valve which is capableof adjusting a flow velocity of introductory gas, and a delivery powderflow velocity control valve which is capable of adjusting a flowvelocity of the powder in the fluidized state within the delivery path.12. The powder filling device of claim 8 wherein the powder fluidizationunit has a gas introducing unit for changing the powder into thefluidized state, and the gas introducing unit is a pressure vessel inwhich the gas is contained in a manner that the gas can be fed to thepowder fluidization unit.
 13. The powder filling device of claim 8wherein the powder fluidization unit has a gas introducing unit forchanging the powder into the fluidized state, and the gas introducingunit is a gas delivery pump with a check valve.
 14. The powder fillingdevice of claim 8 wherein the powder fluidization unit has a gasintroducing unit for changing the powder into the fluidized state, and agas dispensing unit for introducing the gas into the powder fluidizationunit uniformly.
 15. The powder filling device of claim 8 wherein thepowder is a toner for developing an electrostatic latent image.
 16. Apowder filling method for filling up a container with a powder in afluidized state by using a powder filling device which includes ahennitically sealed powder fluidization unit and a powder fillingnozzle, the powder filling nozzle comprising a tubular body having anopening for discharging the powder in the fluidized state into thecontainer, and a gas separating unit disposed near the opening of thetubular body and allowing a gas delivered together with the powder inthe tubular body to pass through the gas separating unit but notallowing the powder to pass through the gas separating unit, wherein thetubular body has a double pipe structure including a first tubular bodyand a second tubular body, the first tubular body being inserted intothe second tubular body so that a gap between the two tubular bodies isformed as a gas delivery path, both ends of the second tubular bodybeing fixed to the first tubular body so as to close the gap, the firsttubular body serving as a delivery path which discharges the powder inthe fluidized state fed from one opening of the first tubular body intothe container through the other opening of the first tubular body, thegas separating unit including a first filter part which does not passthe powder therethrough but allows the gas to pass therethrough, thesecond tubular body having a gas exhausting port connected with anexternal gas suction unit, and the second tubular body having a functionof discharging the gas, passing through the first filter part and beingattracted to the first tubular body by operation of the external gassuction unit, from the gas exhausting port through the gas deliverypath, and wherein the tubular body has a triple pipe structure includinga third tubular body in addition to the first and second tubular bodies,the third tubular body having an inner diameter larger than an outerdiameter of the second tubular body, the second tubular body beinginserted into the third tubular body so that a gap between the secondand third tubular bodies is formed as a second gas delivery path, bothends of the third tubular body being fixed to the second tubular body soas to close the gap between the second and third tubular bodies at bothends thereof, the third tubular body including a second filter part atan outer circumference thereof, the third tubular body having a secondgas exhausting port connected with a second external gas suction unit,and the third tubular body having a function of attracting through thesecond filter part the gas, existing in the powder discharged into thecontainer, by operation of the second gas suction unit, and having afunction of discharging the gas, passing through the second deliverypath between the second tubular body and the third tubular body, fromthe second gas exhausting port the powder filling method comprising thesteps of: mixing the powder contained in the powder fluidization unitwith the gas to obtain the powder in the fluidized state; delivering thepowder in the fluidized state from the fluid fluidization unit into thepowder filling nozzle via a delivery path so that the powder isdischarged into the container from the powder filling nozzle; andsetting the opening of the tubular body in a plugged state by the powderseparated from the gas by the gas separating unit so that the deliveryof the powder from the tubular body to the container is stopped.
 17. Thepowder filling method of claim 16 wherein a bulk density of the powderat a time of delivery is in a range of 0.1 to 0.2.
 18. The powderfilling method of claim 16 wherein a lid member in which the nozzle isinserted and held is fitted in the container, and the powder isdischarged through the nozzle into the container.
 19. The powder fillingmethod of claim 16 wherein the fluidization of the powder into thefluidized state is performed by introducing additional gas into thepowder fluidization unit.
 20. The powder filling method of claim 16wherein the fluidization of the powder with the gas is performed byvibrating the powder fluidization unit.
 21. The powder filling method ofclaim 16 wherein the delivery of the powder from the powder fluidizationunit to the nozzle is performed by increasing a pressure within thepowder fluidization unit.
 22. The powder filling method of claim 16wherein the delivery of the powder from the powder fluidization unit tothe nozzle is performed by applying an external pressure to the powderfluidization unit and decreasing an internal volume of the powderfluidization unit.
 23. The powder filling method of claim 16 wherein thedelivery of the powder in the fluidized state by the powder fluidizationunit is stopped by operation of a first gas suction unit.
 24. The powderfilling method of claim 16 wherein a bulk density of the powder at atime of stopping is in a range of 0.4 to 0.5.
 25. The powder fillingmethod of claim 16 wherein an amount of discharge of the powder in thefluidized state is controlled by regulation of a suction pressure byoperation of the first gas suction unit.
 26. The powder filling methodof claim 23 wherein a gas suction pressure of the first gas suction unitis in a range of −10 kPa to −60 kPa.
 27. The powder filling method ofclaim 16 wherein an amount of discharge of the powder in the fluidizedstate is controlled by regulation of opening and closing of anintroductory gas control valve or a discharge powder flow velocitycontrol valve of the powder fluidization unit.
 28. The powder fillingmethod of claim 16 wherein a gas suction pressure of the second gassuction unit is in a range of −10 kPa to −60 kPa.
 29. The powder fillingmethod of claim 18 wherein, when the container is filled up with a givenamount of the powder, the delivery of the powder is stopped and the lidmember is removed from the container.
 30. The powder filling method ofclaim 16 wherein the powder is a toner for developing an electrostaticlatent image.
 31. A container with which the powder is filled accordingto the powder filling method of claim 16.